It includes simulation of air traffic control features as well as aircraft's on-board systems,[2] and was acclaimed for its highly detailed fully working interactive cockpits.[3] Featured aircraft were exclusively fixed-wing light to medium aircraft. An enhanced version, Fly! 2K, and add-on, Wilco's 737 for Fly!, were released in 2000.[4] A sequel, Fly! II, was released in 2001.